private string CountAndReplaceIndentSpaces(string line, out int count)
{
StringBuilder sb = new StringBuilder();
count = 0;
for (int i = 0; i < line.Length; i++)
{
char c = line[i];
if (c == ' ')
{
sb.Append(' ');
count++;
}
else if (c == '\t')
{
int newCount = CharHelper.AddTab(count);
sb.Append(' ', newCount - count);
count = newCount;
}
else
{
sb.Append(line, i, line.Length - i);
break;
}
}
return(sb.ToString());
}
/// <summary>
/// Parses the indentation from the current position in the line, updating <see cref="StartBeforeIndent"/>,
/// <see cref="ColumnBeforeIndent"/>, <see cref="Start"/> and <see cref="Column"/> accordingly
/// taking into account space taken by tabs.
/// </summary>
public void ParseIndent()
{
var c = CurrentChar;
var previousStartBeforeIndent = StartBeforeIndent;
var startBeforeIndent = Start;
var previousColumnBeforeIndent = ColumnBeforeIndent;
var columnBeforeIndent = Column;
while (c != '\0')
{
if (c == '\t')
{
Column = CharHelper.AddTab(Column);
}
else if (c == ' ')
{
Column++;
}
else
{
break;
}
c = Line.NextChar();
}
if (columnBeforeIndent == Column)
{
StartBeforeIndent = previousStartBeforeIndent;
ColumnBeforeIndent = previousColumnBeforeIndent;
}
else
{
StartBeforeIndent = startBeforeIndent;
ColumnBeforeIndent = columnBeforeIndent;
}
}
/// <summary>
/// Appends the specified line to this instance.
/// </summary>
/// <param name="slice">The slice.</param>
/// <param name="column">The column.</param>
/// <param name="line">The line.</param>
/// <param name="sourceLinePosition"></param>
public void AppendLine(ref StringSlice slice, int column, int line, int sourceLinePosition)
{
if (Lines.Lines == null)
{
Lines = new StringLineGroup(4);
}
var stringLine = new StringLine(ref slice, line, column, sourceLinePosition);
// Regular case, we are not in the middle of a tab
if (slice.CurrentChar != '\t' || !CharHelper.IsAcrossTab(column))
{
Lines.Add(ref stringLine);
}
else
{
// We need to expand tabs to spaces
var builder = StringBuilderCache.Local();
for (int i = column; i < CharHelper.AddTab(column); i++)
{
builder.Append(' ');
}
builder.Append(slice.Text, slice.Start + 1, slice.Length - 1);
stringLine.Slice = new StringSlice(builder.ToString());
Lines.Add(ref stringLine);
}
}
/// <summary>
/// Unwind any previous indent from the current character back to the first space.
/// </summary>
public void UnwindAllIndents()
{
// Find the previous first space on the current line
var previousStart = Line.Start;
for (; Line.Start > originalLineStart; Line.Start--)
{
var c = Line.PeekCharAbsolute(Line.Start - 1);
if (c == 0)
{
break;
}
if (!c.IsSpaceOrTab())
{
break;
}
}
var targetStart = Line.Start;
// Nothing changed? Early exit
if (previousStart == targetStart)
{
return;
}
// TODO: factorize the following code with what is done with GoToColumn
// If we have found the first space, we need to recalculate the correct column
Line.Start = originalLineStart;
Column = 0;
ColumnBeforeIndent = 0;
StartBeforeIndent = originalLineStart;
for (; Line.Start < targetStart; Line.Start++)
{
var c = Line.Text[Line.Start];
if (c == '\t')
{
Column = CharHelper.AddTab(Column);
}
else
{
if (!c.IsSpaceOrTab())
{
ColumnBeforeIndent = Column + 1;
StartBeforeIndent = Line.Start + 1;
}
Column++;
}
}
// Reset the indent
ColumnBeforeIndent = Column;
StartBeforeIndent = Start;
}
/// <summary>
/// Returns the next character in the line being processed. Update <see cref="Start"/> and <see cref="Column"/>.
/// </summary>
/// <returns>The next character or `\0` if end of line is reached</returns>
public char NextChar()
{
var c = Line.CurrentChar;
if (c == '\t')
{
Column = CharHelper.AddTab(Column);
}
else
{
Column++;
}
return(Line.NextChar());
}
/// <summary>
/// Moves to the position to the specified column position, taking into account spaces in tabs.
/// </summary>
/// <param name="newColumn">The new column position to move the cursor to.</param>
public void GoToColumn(int newColumn)
{
// Optimized path when we are moving above the previous start of indent
if (newColumn >= ColumnBeforeIndent)
{
Line.Start = StartBeforeIndent;
Column = ColumnBeforeIndent;
}
else
{
Line.Start = originalLineStart;
Column = 0;
ColumnBeforeIndent = 0;
StartBeforeIndent = originalLineStart;
}
for (; Line.Start <= Line.End && Column < newColumn; Line.Start++)
{
var c = Line.Text[Line.Start];
if (c == '\t')
{
Column = CharHelper.AddTab(Column);
}
else
{
if (!c.IsSpaceOrTab())
{
ColumnBeforeIndent = Column + 1;
StartBeforeIndent = Line.Start + 1;
}
Column++;
}
}
if (Column > newColumn)
{
Column = newColumn;
if (Line.Start > 0)
{
Line.Start--;
}
}
}